1. Field of the Invention
The present invention relates to interior parts for a vehicle (hereinafter referred to as an “interior part”) and more particularly to a mounting structure of a vehicular interior part to vehicle body portions having air bag components disposed therein.
2. Description of the Prior Art
In recent automobiles, in order to protect a vehicle occupant from an impact caused by a side collision accident or the like, a side air bag apparatus is installed inside a side portion of a seat back for protecting the upper body of the vehicle occupant, and also put to practical use is a curtain air bag apparatus is also installed inside a vehicle portion running from the front pillar to the roof side frame (and to the rear pillar) for protecting the head of the vehicle occupant.
FIG. 13 is a cross sectional view of an air bag 14 of a curtain air bag apparatus AU expanded and developed within the interior of a vehicle.
The curtain air bag apparatus AU includes an air bag 14 and an inflator (not shown) which is disposed in the lower portion or the like of the front pillar 10. The air bag 14 is, as shown in FIG. 14, folded and accommodated in a space D that is defined by the inner side of a front pillar garnish PG1 of the front pillar 10 and the back side of a roof side garnish RG1 (see FIG. 13). When a collision detecting sensor detects impact, the inflator operates to instantly deploy the air bag 14 in the vehicle interior, thereby covering the side window glass 18 with the deployed air bag 14.
In the curtain air bag apparatus AU, various types of air bags have been put to practical use. For example, in one type of air bag shown in FIG. 13, the air bag extends from the front pillar garnish PG1 to the roof side garnish RG1, and in another type, the air bag extends only to a portion of the roof side garnish RG1. In the case of the former type, an air bag supporting member 16 and a part of the air bag 14 are accommodated inside the front pillar garnish PG1. On the other hand, in the case of the latter type, the air bag supporting member 16 is accommodated inside the front pillar garnish PG1. In the following description, both the air bag 14 and the air bag supporting member 16 are collectively referred to as “air bag components” as well.
As shown by broken lines in FIG. 13, the air bag 14 and the air bag supporting member 16 that form the air bag components are accommodated inside the front pillar garnish PG1 and roof side garnish RG1. In the front pillar garnish PG1, as shown in FIG. 14, a weather strip 24 disposed along the front pillar 10 is brought in tight contact with the edge portion of the front pillar garnish PG1. The roof side garnish RG1 has the same construction as that of the front pillar garnish PG1. Hence, neither the air bag 14 nor the air bag supporting member 16 is exposed to the interior of the vehicle. When the curtain air bag apparatus AU operates upon collision of the vehicle, a gap through which the air bag 14 or the air bag supporting member 16 is made to pass is formed in a boundary portion between the front pillar 10 and the front pillar garnish PG1, or in a boundary portion between the roof side frame 12 and the roof side garnish RG1.
For example, in the front pillar garnish PG1 shown in FIG. 14, one or plural mounting brackets 32 are formed on the inner side of a garnish main body 30, which is able to cover the front pillar 10, so as to protrude from the inner side of the garnish main body 30. Thus, the front pillar garnish PG1 is mounted to the front pillar 10 through a mounting clip 40 installed in the mounting bracket 32. More specifically, as shown in FIG. 16(a), the mounting clip 40 is comprised of:                (a) an engagement fixing portion 44 which is formed on one side of the flange portion 42 and which is adapted to be inserted and engaged with an engagement hole 11 (see FIG. 14) of the front pillar 10;        (b) a flexible portion 46, with a total length L (see FIG. 16(a)), which is formed on the other side of the flange portion 42 so as to be longer than the protrusion height H of the mounting bracket 32;        (c) a first engaging portion 48 which is on a proximal end side of the flexible portion 46; and        (d) a second engaging portion 50 which is on a distal end side of the flexible portion 46.        
The second engaging portion 50 and the flexible portion 46 of the mounting clip 40 are inserted into the accommodating space 36 of the mounting bracket 32 through an engaging hole (engagement receiving portion) 34 which is provided in the top portion of the mounting bracket 32 so that the first engaging portion 48 of the mounting clip 40 engages the engaging hole 34. As a result, the mounting clip 40 is installed in the front pillar garnish PG1. In other words, the front pillar garnish PG1 is engaged with the first engaging portion 48 of the mounting clip 40 and is thus attached to the front pillar 10.
When the above-mentioned curtain air bag apparatus AU operates, the air bag 14 and/or the air bag supporting member 16 presses against the garnish main body 30 from its inner side so that the engagement of the first engaging portion 48 with the engaging hole 34 is released. As a result, as shown in FIG. 15, at least one portion of the front pillar garnish PG1 moves to the vehicle interior side for a distance that the second engaging portion 50 comes to engage the engaging hole 34 (or a distance nearly corresponding to the total length L of the flexible portion 46), so that a gap S enough for the air bag 14 and the air bag supporting member 16 to protrude is formed between the garnish main body 30 and the front pillar 10.
The roof side garnish RG1 has substantially the same construction as that of the front pillar garnish PG1 and this construction is disclosed in, for example, Japanese Patent Application Laid-Open (Kokai) No. 2003-95033.
In the above structure, in order to sufficiently secure the gap S through which the air bag 14 and the air bag supporting member 16 can protrude, as shown in FIG. 16(a), the total length L of the flexible portion 46 of the mounting clip 40 is set longer than the protrusion height H of the mounting bracket 32 in many cases. In such a size setting, as shown in FIG. 16(b) and disclosed in Japanese Patent Application Laid-Open (Kokai) No. 2003-95033, when the first engaging portion 48 of the mounting clip 40 is engaged with the engaging hole 34 of the mounting bracket 32, the distal end of the second engaging portion 50 of the mounting clip 40 inside the accommodating space 36 comes in contact with the inner surface of the garnish main body 30, so that the flexible portion 46 of the mounting clip 40 is bent inside the accommodating space 36.
However, as can be understood from FIG. 16(a), since the insertion direction (engaging direction) of the flexible portion 46 and the extension direction of the flexible portion 46 agree with each other, when the second engaging portion 50 of the mounting clip 40 touches the inner surface of the garnish main body 30, the flexible portion 46 of the mounting clip 40 hardly bends. In other words, since the flexible portion 46 has a strong resistance force against the flexibly bending deformation, the flexible portion 46 does not bend unless the mounting clip 40 is pushed into the accommodating space 36 with a considerably strong force. As a result, an excessive stress concentrates on the touch portion where the second engaging portion 50 touches the inner surface of the garnish main body 30, so that an outer surface side of the garnish main frame 30 corresponding to the touch portion changes its color to white to cause texture deterioration. In addition, since a large force is required for installing the mounting clip 40, there is also a problem that a burden imposed on a worker increases and thus a number of operating time is required for the installation work.
In addition, as shown in FIG. 16(a), during the installation of the mounting clip 40, the insertion direction of the second engaging portion 50 and flexible portion 46 of the mounting clip 40 which are brought into the accommodating space 36 through the engaging hole 34 becomes nearly vertical to the inner surface of the garnish main body 30. In this case, since the difference between the total length L of the flexible portion 46 of the mounting clip 40 and the protrusion height H of the mounting bracket 32 is at its maximum, the deformation amount of the flexible portion 46 inevitably increases. Therefore, after the mounting clip 40 is installed in the mounting bracket 32, a pressing force caused by a return elastic force of the flexible portion 46 concentrates on the garnish main body 30. For this reason, when a thermal history is applied, the touch portion in the garnish main body 30 is expansively deformed toward the outer surface in some cases, and deterioration in texture of the garnish main body 30 due to its expansive deformation is also a problem.